I'm not sure what happened, but I also didn't read 8 pages of comments. I have used Chemi-Clean (and RedCyano Rx) dozens of times over the years, and have recommended it to anyone dealing with a cyano outbreak. I've never had a single thing die in any system I treated, other than getting rid of the red crap accumulated on the sandbed and rocks.
And I'll point out that at one time, I had such a stubborn strain I used it at 200% strength because nothing else had worked. That got rid of it, and my reef looked great. If I have time, I'll re-read this thread to see what happened, but for now I'll post what I recommend to others:
"To treat your tank with best results, it would be best to siphon out as much of the cyano bacteria out of your tank first. Reducing the volume of red slime from the aquarium helps avoid issues. Be sure to point one powerhead at the surface to get strong rippling, which improves oxygenation of the water. Plugging in an airpump and airstone to add oxygen to the water is another good idea, especially in tanks with low flow.
Turn off the protein skimmer, and stop running carbon and GFO. The tank can be treated day or night, and all of your livestock is safe. While the tank is being treated, start mixing up new saltwater because a big water change is next. After 72 hours, check the tank and if the cyano is gone, do a 25% or larger water change. If cyano is still present, wait another 24 hours. If it is still present, treat the tank again. Once the cyano is gone, do the big water change. The bigger, the better, because the product will cause protein skimmers to oveflow initially. Adjust the skimmer to the lowest water level in the body, and as the collection cup fills with watery skimmate, toss it out. Keep tossing out skimmate and replenish the system with more saltwater. After a few hours, the skimmer should settle down finally. If microbubbles are getting the best of you, put a filter sock on the output of the skimmer for the first day. "